1. Field of the Invention
The present invention relates to a method of making a biodegradable particulate absorbent material which is especially adapted for use as animal litter, caulking filler material, packaging material or floor sweep and to the products of the method.
2. Description of the Prior Art
Several types of litter material are known. For example, litter materials made from clay, alfalfa, wood chips or sawdust and paper are known. Some of these materials have serious disadvantages when used as litter.
Clay, because of its high density, is very heavy and thus cannot be carried in large quantities by the consumer. Clay litter typically has a density of about 0.6 g/cc. Further, clay cannot be disposed of directly on a lawn or in the garden.
Alfalfa pellets also have serious deficiencies because these types of litter are edible by bacteria and thus tend to mold and develop unpleasant odors. U.S. Pat. No. 3,789,797 (Brewer) discloses a cat litter product prepared from an alfalfa base.
Litter made from sawdust or wood chips is ineffective because it has a wood odor that is unpleasant to many animals. In addition, these pellets are not very absorbent because they include lignin, wood tars and turpentines. An example of litter made from bark and fiber crumbs is disclosed in U.S. Pat. No. 3,980,050 (Neubauer).
U.S. Pat. No. 4,263,873 (Christianson) relates to an animal litter including a cellulose litter material which contains a pheromone attractant substance which makes the litter attractive to animals. The cellulose material is made from pelletized ground paper having a sufficient moisture content to hold the particles together. A significant disadvantage of this animal litter is that it requires many steps to produce as can be seen from FIG. 1 of this patent.
U.S. Pat. No. 4,621,011 (Fleischer et al) discloses a cellulosic particle especially useful as cat litter which is manufactured by agglomerating a fibrous cellulosic feed material in the presence of water, compacting the surface of the agglomerated particles and drying the particles. A significant disadvantage of this cat litter is that it also requires several steps to produce including fiberization by attrition, hydration, agglomeration and compaction.
U.S. Pat. No. 4,560,527 relates to a method of making agglomerated cellulosic particles which are useful as cat litters. The process comprises agglomerating a moist blend of fibers, aggregates of fibers and/or fiber-size pieces of fibrous cellulosic material in a substantially horizontal rotating drum to form agglomerated particles, compacting the surfaces of the particles and drying the particles. Again, this process requires numerous steps which render it costly and inefficient.
U.S. Pat. No. 4,570,573 relates to a cat litter composition which is absorbent, odorless, trackless and biodegradable. The cat litter composition comprises 60-94% by weight of a paper, 1-35% by weight gypsum and about 3-12% by weight of water. The composition is pelletized so that it may easily be disposed of by flushing it down the toilet. One disadvantage of this product is that it employs gypsum which tends to adhere to the cat who then leaves paw prints around the house. As a result, this cat litter must also be pelletized in order to prevent dusting.
Compacted and pelletized products are disadvantageous because they are costly to produce and, because they lack mechanical entanglement, these products tend to expand and fall apart when they are wet.
Other uses for the waste paper product of the invention are for making packaging material and floor sweep. A disadvantage of commercially available packaging material is that it easily creases or bends thus making it poor for packaging items such as art prints.
The present invention is directed to overcoming the deficiencies in the prior art, providing a very simple and easy way to produce inexpensive, biodegradable animal litter, packing material, floor sweep, and caulking filler material for wood, wallboard and plaster from waste paper products. Further, the present invention will help dispose of the glut of waste paper currently being collected by municipalities in successful recycling programs.